This project seeks to evaluate the most promising means to eradicate infections caused by 0eriodontal disease pathogens. Considering that scaling and root planing (SRP) is likely to be essential to rid sites of plaque biofilms and infected calculus, four adjunctive strategies appear likely to substantially contribute to the transmission, disinfection of pathogen reservoirs and elimination of environments that support growth of periodontal pathogens. Based on a review of microbiologic responses described in our previous studies and in the literature, the strategies most likely to eliminate or suppress the periodontal pathogens were identified. Reduction of supragingival plaque will be achieved by providing powered toothbrushes and triclosan/co-polymer dentifrice to all subjects. Control of pathogen transmission will be by chlorhexidine (CHX) mouth-rinses for two weeks following completion of therapy. Disinfection of pathogen reservoirs will be by application of tetracycline (TC) fibers in all pockets > 3mm. Elimination of environments that support growth of periodontal pathogens will be by periodontal surgery. The proposal describes a unique 2/3 factorial design in which local antibiotics, systemic antibiotics and periodontal surgery will be compared as adjunctive treatments following SRP in subjects receiving electric toothbrushes and triclosan-co-polymer dentifrice. The experimental design provides the potential for high statistical sensitivity by evaluating main effects through combined analysis of 4 of the 8 experimental groups. In addition, the model provides a means to evaluate important interactions between each of the treatments being tested. Although this study addresses important questions related to clinical practice, it also provides information on biological effects of various forms of therapy and identifies the most important directions to be taken in future investigations.